PHP裁剪图像以固定宽度和高度而不会丢失尺寸比率

function cropImage($source, $destination, $width, $height) {
    // 获取原始图像的尺寸
    list($sourceWidth, $sourceHeight, $sourceType) = getimagesize($source);

    // 计算新的尺寸
    $ratio = min($width / $sourceWidth, $height / $sourceHeight);
    $newWidth = $sourceWidth * $ratio;
    $newHeight = $sourceHeight * $ratio;

    // 创建新的图像资源
    $newImage = imagecreatetruecolor($width, $height);
    $sourceImage = imagecreatefromstring(file_get_contents($source));

    // 保持PNG和GIF透明度
    imagealphablending($newImage, false);
    imagesavealpha($newImage, true);
    $transparent = imagecolorallocatealpha($newImage, 255, 255, 255, 127);
    imagefilledrectangle($newImage, 0, 0, $width, $height, $transparent);

    // 将原始图像缩放并裁剪
    imagecopyresampled($newImage, $sourceImage, ($width - $newWidth) / 2, ($height - $newHeight) / 2, 0, 0, $newWidth, $newHeight, $sourceWidth, $sourceHeight);

    // 保存新的图像
    switch ($sourceType) {
        case IMAGETYPE_GIF:
            imagegif($newImage, $destination);
            break;
        case IMAGETYPE_JPEG:
            imagejpeg($newImage, $destination);
            break;
        case IMAGETYPE_PNG:
            imagepng($newImage, $destination);
            break;
        default:
            return false;
    }

    // 销毁图像资源
    imagedestroy($newImage);
    imagedestroy($sourceImage);

    return true;
}